Rotary spool valve

ABSTRACT

The specification discloses a spool valve including a spool mounted within a passage within a valve body. The spool can be rotated by means of a knob and includes a pin extending into a helical slot in the valve body such that rotation of the spool results in its axial movement to thereby control the flow of fluid between various lateral passages extending through the valve body and communicating with the passage therethrough. A spring-biased ball held by the valve body rides across a camming surface on the spool to provide a detent for spool movement and to bias the spool towards either one or the other of its possible positions.

United States Patent [151 3,707,168 Boelkins [4 1 Dec. 26, 1972 [54]ROTARY SPOOL VALVE 2,684,691 7 1954 Strickler ..l37/625.4 x 3,044,4917/1962 Sangster ...l37/625.48 X [72] Invent f' Bwklns, Grand 3,270,3609/1966 Kropp ..74/56 Mlch- 3,324,886 6/1967 Way ..l37/625.48 AssigneezInc, Grand p 3,402,642 9/1968 Hecke 8! 8| ..l37/625.48 X

[ Filed: p 1970 Primary Examiner-Samuel Scott [21] APPL NM 76,695Attorney-Price, Heneveld, Huizenga & Cooper [57] ABSTRACT [22] {1.8.81The specification discloses a spool valve including a l!- spool mountedwithin a p g within a valve [58] Field of Search ..l37/625.4, 625.46,625.48, The spool can be rotated by means of a knob and 137/625'39614-11; 74/5615. cludes a pin extending into a helical slot in the valvebody such that rotation of the spool results in its axial Rflel'encesCited movement to thereby control the flow of fluid between variouslateral passages extending through UNITED STATES PATENTS the valve bodyand communicating with the passage 3,156,271 11/1964 Schnurmann..251/340X therethrough. A spring biased ball held by the valve3,367,626 2/1968 Stern ..'......251/340 body rides across a cammingsurface on the spool to 3,482,740 12/1969 Evans et a1. 137/6254 Xprovide a detent for spool movement and to bias the 3,503,540 3/1970Fuerstt 137/6254 X spool towards either one or the other of its possible3,492,880 2 1970 Pearson.... ..74 s7 positions 3,389,639 6/1968 Asche..l37/625.48 X 3,563,349 2/1971 Spieth et a1 ..137/614.11 X 6 Claims, 6Drawing Figures 29 2 l7 u 2 la l 2.8 IO G1 PATENTED DEB 2 s 1912 SHEET 1OF 2 FIG. 2

FIG.

INVENTOR. ZUAHLACE 6. 5064mm ROTARY SPOOL VALVE BACKGROUND Thisinvention relates to spool valves. Conventionally, these valves comprisea spool mounted for axial movement within an internal passage in a valvebody. By shifting the spool axially, one can control the flow of fluidbetween various lateral passages in the spool body which communicatewith the internal passage.

There are a number of drawbacks to such conventional spool valves. Firstof all, it is difficult to tell at a glance what relative flow controlposition the spool is in with respect to the valve body. This is becauseonly a small amount of axial shifting is required to vary the flowresult. Thus, one cannot tell whether the spool is set to allow flowbetween a given pair of passages or to block flow therebetween.

Spool valves may include resilient sealing members, such as rubberO-rings, mounted on the spools to constitute a flow blocking or sealingmeans, but in order to adjust the valve between a flow and non-flowcondition, one must move the resilient seal past the opening of alateral passage. The resulting abrasion between the edges of the openingand the resilient seal causes considerable wear and tear on the seal andminimize its life expectancy.

The present invention comprises a spool valve having a spool mounted inan internal passage in a valve body for controlling fluid flowtherethrough. In accordance with this invention, however, means areprovided for rotating the spool and for moving the spool axially withrespect to the valve body in response to such rotation. Because thespool is in effect rotated between flow and non-flow positions, thespool rotating means can be provided with an indicator whereby therelative position of the spool within the valve body can be definitelyand unmistakably ascertained merely by glancing at the indicator.Furthermore, actuation is readily accomplished in a very sure andpositive manner.

In other aspects of the invention, the spool-moving means comprises ahelical guide such that a given point of the surface of the spooldescribes a generally helical path during rotation of the spool. Thus,O-rings may be used as seals, since as the same move past an openingfrom a lateral passage, they do so through a helical path and therebyundergo much less wear and tear than would be the case if they weredrawn or dragged straight across the passage opening. Wear and tear isfurther minimized by providing the lateral passage past which the O-ringtravels with two smaller openings into the axial valve passage ratherthan one larger opening.

In another aspect of the invention, the spool is biased alternatively toa first or second axial position whereby rotation of the spool resultsin a positive shift thereof from one of its axial positions to theother. This results in positive on-off control and thereby furtherimproves the ease with which the relative position of the spool withinthe valve body can be determined.

BRIEF DESCRIPTION OF THE DRAWINGS These and other objects and advantagesof this invention will be better understood and appreciated by referenceto the appended specification and drawings wherein: I

Illl

FIG. 1 is a partial cross-sectional side elevational view of the spoolvalve with the spool being shown in a first axial position;

FIG. 2 is a partial cross-sectional view of the spool valve with thespool being shown in a second axial position;

FIG. 3 is a plan view of the spool alone;

FIG. 4 is a cross section taken along the plane IV IV of FIG. 3;

FIG. 5 is a top plan view of the spool valve; and

FIG. 6 is a bottom plan view of the spool valve with the front portionbroken away.

PREFERRED EMBODIMENT In the preferred embodiment, the inventioncomprises a spool 10 mounted within a valve body 20. Spool 10 can berotated by means of a knob mounted thereon and is shifted axially withrespect to valve body 20 in response to such rotation due to the actionof a helical guide assembly 40 (FIGS. 1, 2 and 5). A bias assembly 50biases spool 10 alternatively to either a first axial position as shownin FIG. 1 or to a second axial position as shown in FIG. 2. Adetermination of which relative position spool 10 is in can be made byobserving the angular position of knob 60 with respect to an indicatorplate 70.

Spool 10 is mounted for rotational and axial movement within an axialpassage 21 which extends through the center of valve body 20 (FIGS. 1and 2). The flowcontrolling section of spool 10 is flanked by a frontbearing portion 15 and by a rear bearing portion 16 (FIG. 3). Thesebearing portions have diameters which are approximately equal to (i.e.,closely approach) the inside diameter of axial passage 21. Theflow-controlling area of spool 10 comprises a shaft which is dividedinto a front fluid passing portion 11 and a rear fluid passing portion12 by a flexible O-ring 13 which is held in position by a pair of radialflanking ribs 14 which are integral with the spool. A front seal isprovided by a front O-ring 17 held in place by front bearing portion 15and a rib 17a, and a rear seal is provided by a similar flexible O-ring18 which is held in place by rear bearing portion 16 and a rib 18a.Portions 11 and 12 are narrower in diameter than the inside diameter ofaxial passage 21 such that fluid is free to flow within these portions,between the spool and the valve body (FIGS. 1 and 2).

Valve body 20 comprises a central portion 22 (FIG. 5) having a hexagonalcross section in this particular embodiment, a rear cylindricalextension 23 and a front threaded extension 24 (FIG. 5). Axial passage21 extends from the front of valve body 20 to the rear thereof, throughall three of these sections 22, 23 and 24.

Extending laterally inwardly through the central portion of valve body20 are a first threaded passage25, a second threaded passage 26 and athird threaded passage 27 (FIGS. 1 and 2). First threaded passage 25communicates directly with axial passage 21. However, second passage 26communicates with axial passage 21 through a pair of adjacent fluid flowpassages 28 which are considerably smaller in diameter than threadedpassage 26 (FIGS. 1, 2 and 6). Third threaded passage 27 communicateswith axial passage 21 through a single lateral fluid passage 29 which issmaller in diameter than threaded passage 27. The combinedcross-sectional area of the two passages 28 may be equal to or greaterthan the cross-sectional area of the passag'e'29, even though thepassages 28 are smaller in diameter than passage 29, such that the fluidflow capacity through the two passages 28 will be equal to or greaterthan the fluid flow capacity of the single passage 29.

Helical guide assembly 40 includes a pin 41 which is rigidly mounted onthe end portion 16 of spool 10 (FIG. 3), as by being press-fitted into ahole which extends laterally through end portion 16 of spool 10. Pin 41extends laterally from spool 10'and into a helical slot 42 which is cutinto the cylindrical extension 23 of valve body 20 (FIG. 5). Preferably,slot 42 extends through an arc of 90 or more, and extends an axialdistance sufficient to allow spool to shift from its first to its secondaxial position. An access opening 43 (FIG. 6) is provided on theopposite side of cylindrical extension 23 so that if removal of spool 10from valve becomes necessary, a tool can be inserted into opening 43 andpin 41 can be driven out the opposite side.

Bias assembly 50 comprises a small ball 51 which is seated in adepression in portion 11 of spool 10. Ball 51 protrudes from the surfaceof spool 10 to provide a camming surface (FIGS. 1, 2 and 4). As with anyother spot on the surface of spool 10, this camming surface will bemoved along a helical path when spool 10 is rotated. Positioned at thecenter of that helical path is a ball 52 which is mounted for lateralmovement within first passage of valve body 20. Ball 52 is biasedtowards engagement with spool 10 by a spring 53, held in place withinfirst threaded passage 25 by a threaded cap fitting 54 (FIGS. 1, 2 and5). Cap 54 includes a narrow flow passage 55 therethrough such that theaxial passage 21 in the valve body can be vented through first threadedpassage 25 and flow passage 55.

Knob 60 can be any conventional knob having a pointer portion 61 and canbe held on the end of spool 10 by means ofa set screw 62 (FIG. 3). Therelative angular position of knob 60 can be determined by observing therelative position of pointer 61 with respect to indications on anindicator plate 70. The latter is secured to the front of valve body 20by being slipped over front threaded portion 24 and held in place bymeans of a securing nut 71. Preferably, indicator plate 7i) and the rearof threaded portion 24 include inter-fitting indexing portions such asmating irregularities, such that indicating plate 70 is properlyoriented or indexed as soon as it is secured to valve body 20.Generally, indicator plate 70 will be provided with an on indication andan of indication to indicate either the existence or the non-existenceof fluid flow between second threaded passage 26 and third threadedpassage 27.

OPERATION In operation, three fluid flow lines may be secured to valvebody 20. Of these, a first feed line will be secured to second threadedpassage 26, and fluid flowing therethrough will flow either to a line inflow communication with threaded passage 25 and fluid flow passage 55 orto a line communicating through threaded passage 27 and flow passage 29.The flow line in communication with passage 55 might well be a returnline which would allow one to block the flow of fluid to threadedpassage 27 without creating a pressure buildup in the feed line tosecond passage 26.

When spool 10 is in its first axial position as shown in FIG. 1, fluidwill flow through threaded passage 26 and through the two narrower flowpassages 28 into the axial passage 21. From thence it will flow out ofvalve body 20 through fluid passage 29 and third threaded passage 27.When spool 10 is in this position, pointer 61 of knob 60 will point toan on indication on indicator plate 70.

Spool 10 can be moved to its second axial position as shown in FIG. 2 byrotating knob 60. As spool 10 is rotated, pin 41 follows helical slot 42in valve body 20. Thus, if one is rotating spool 10from the positionindicated in FIG. 1, it tends to slide rearwardly (i.e., further intothe valve body) until pin 41 contacts the opposite end of helical slot42. In the alternative, as spool 10 is turned from its off position asindicated in FIG. 2, it slides forwardly due to the action of pin 41following helical slot 42.

Ball 52 and spring 53 act to bias spool 10 alternatively to either thefirst or second axial position. This insures positive on-off control ofthe valve. As knob 60 is rotated, ball 51 passes beneath ball 52.Because ball 51 comprises a protruding cam surface, ball 52 is forcedupwardly against the action of spring 53. Once spool 10 has been rotateda certain distance, ball 51 will pass top center of ball 52 and willthen be forced to the opposite side thereof by the downward forceexerted on ball 52 by spring 53. Thus, one wiil rotate knob 60 a certaindistance until the biasing action of ball 52 and spring 53 on ball 51take over and automatically force spool 10 to rotate the rest of the wayinto its second axial position as shown in FIG. 2. One can therebyalways be sure that the spool 10 is either in its first or second axialposition and not somewhere in between.

When spool 10 is in the position shown in FIG. 2, fluid flow from thepassages 28 to passage 29 is prevented by the presence of O-ring 13therebetween. However, fluid does flow into axialpassage 21 and outthrough fluid passage 55 in cap 54. As stated before, this could be areturn line to a reservoir whereby a pump on the feed line connected tosecond threaded passage 26 could continue to operate without building uppressure. When spool 10 is in its second axial position as shown in FIG.2, pointer 61 on knob 60 would point to an off indication on indicatorplate 70.

The relative axial position of the spool can be readily determined byreference to a pointer on knob 60. Because helical slot 42 describes anarc of about knob 60 is also rotated through the same are, and thus itsrelative position is readily apparent. Further, one can always be surethat the valve is in either its on" or of position and not somewhere inbetween. If this were a conventional spool valve, it would beconsiderably more difficult to determine the relative axial position ofspool 10 since it only need be moved a relatively short axial distancein order to change the flow condition of the valve.

Furthermore, the helical motion of resilient O-ring 13 past the smallpassages 28 results in much less wear and tear on O-ring 13 than wouldbe the case f the latter were drawn directly, i.e., axially, across thesurfaces of these openings. Additionally, the fact that two smalleropenings are used in place of one larger one further reduces the wearand tear on O-ring 13, since this measure helps to eliminate the gougingor digging effect which the edges of larger openings inevitably haveupon O-rings or like resilient sealing members.

It is understood that the above is merely a preferred embodiment of theinvention and that a number of changes and alterations can be madethereof without departing from the spirit and broader aspects of theinvention.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows.

1. A spool valve comprising a spool mounted in a valve body forcontrolling fluid flow therethrough in response to axial spoolmovements; means for rotating said spool; means for moving said spoolaxially with respect to said body in response to the rotation of saidspool comprising a slot of axially and laterally curved configurationdefined by one of said body or said spool and a pin means projectinglaterally from the other of said body and spool and extending into saidslot such rotation of the spool with respect to said body producesdirect axial movement therebetween as a result of the forced movement ofthe pin means within the said slot; and means for biasing said spoolinto one of at least two axial positions upon rotation of said spool,such that rotation results in a biased shift from one of said axialpositions to another.

2. A spool valve comprising a spool mounted in a valve body forcontrolling fluid flow therethrough in response to axial spoolmovements; means for rotating said spool; means for moving said spoolaxially with respect to said body in response to the rotation thereofcomprising means for guiding the movement of said spool such that apoint on its surface describes a generally helical path during saidrotation thereof; an internal passage within said valve body, and saidspool disposed in said passage; means for securing at least two fluidlines to said valve body, between which flow is to be controlled; saidfluid line-connecting means comprising one lateral passage connectingone such line to said internal passage and at least two lateral passagesconnecting the other such line to said internal passage, the combinedcross-sectional area of said two passages being approximately equal toor greater than the crosssectional area of said one passage; a resilientsealing member being secured to said spool in a position for movementwith said spool from a position between said one lateral passage andsaid two lateral passages past said two lateral passages, whereby all ofsaid lateral passages communicate through said internal spool passage.

3. A spool valve comprising: a spool mounted in an internal passage in avalve body for controlling fluid flow therethrough; means for rotatingsaid spool; pin means projecting laterally from said spool into agenerally helical slot in said valve body whereby rotation of said spoolresults in axial movement thereof; a cam surface projecting laterallyfrom the surface of said spool; -a ball mounted in a passage in saidvalve body extending laterallyof said internal passage and being biasedby a spring means in said lateral passage into the path followed by saidcam surface such that rotation of said spool causes said cam surface tobe cammed either to one side or the other ofsaidball.

4. The spool valve of claim 3 which comprises a first means and a secondmeans for conducting a flow of fluid through said valve body and beingin flow communication with said internal passage; said spool including aresilient sealing means secured thereto for movement therewith, from aposition between said first and second flow means, past said first flowmeans to a position between said first flow means and said lateralpassage; said lateral passage including a third'means for conducting aflow of fluid through said valve body and being in flow communicationwith said passage.

5. The spool valve of claim 4 in which said second fluid flow meanscomprises a second passage extending laterally of and into said internalpassage and said first fluid flow means comprises a plurality ofadjacent passages extending laterally of and into said internal passagewhose combined cross-sectional area is equal to or greater than thecross-sectional area of said second lateral passage.

6. A spool valve comprising a spool mounted in a valve body forcontrolling fluid flow therethrough in response to axial spoolmovements; an internal passage within said valve body, and said spooldisposed in said passage; means for securing at least two fluid lines tosaid valve body, between which flow is to be controlled; said fluidline-connecting means comprising one lateral passage connecting one suchline to said internal passage and at least two lateral passagesconnecting the other such line to said internal passage, the combinedcross-sectional area of said two passages being approximately equal toor greater than the cross-sectional area of said one passage; aresilient sealing member being secured to said spool in a position formovement with said spool from a position between said one lateralpassage and said two lateral passages past said two lateral passages,whereby all of said lateral passages communicate through said internalspool passage.

l060l2 OlOO

1. A spool valve comprising a spool mounted in a valve body forcontrolling fluid flow therethrough in response to axial spoolmovements; means for rotating said spool; means for moving said spoolaxially with respect to said body in response to the rotation of saidspool comprising a slot of axially and laterally curved configurationdefined by one of said body or said spool and a pin means projectinglaterally from the other of said body and spool and extending into saidslot such rotation of the spool with respect to said body producesdirect axial movement therebetween as a result of the forced movement ofthe pin means within the said slot; and means for biasiNg said spoolinto one of at least two axial positions upon rotation of said spool,such that rotation results in a biased shift from one of said axialpositions to another.
 2. A spool valve comprising a spool mounted in avalve body for controlling fluid flow therethrough in response to axialspool movements; means for rotating said spool; means for moving saidspool axially with respect to said body in response to the rotationthereof comprising means for guiding the movement of said spool suchthat a point on its surface describes a generally helical path duringsaid rotation thereof; an internal passage within said valve body, andsaid spool disposed in said passage; means for securing at least twofluid lines to said valve body, between which flow is to be controlled;said fluid line-connecting means comprising one lateral passageconnecting one such line to said internal passage and at least twolateral passages connecting the other such line to said internalpassage, the combined cross-sectional area of said two passages beingapproximately equal to or greater than the cross-sectional area of saidone passage; a resilient sealing member being secured to said spool in aposition for movement with said spool from a position between said onelateral passage and said two lateral passages past said two lateralpassages, whereby all of said lateral passages communicate through saidinternal spool passage.
 3. A spool valve comprising: a spool mounted inan internal passage in a valve body for controlling fluid flowtherethrough; means for rotating said spool; pin means projectinglaterally from said spool into a generally helical slot in said valvebody whereby rotation of said spool results in axial movement thereof; acam surface projecting laterally from the surface of said spool; a ballmounted in a passage in said valve body extending laterally of saidinternal passage and being biased by a spring means in said lateralpassage into the path followed by said cam surface such that rotation ofsaid spool causes said cam surface to be cammed either to one side orthe other of said ball.
 4. The spool valve of claim 3 which comprises afirst means and a second means for conducting a flow of fluid throughsaid valve body and being in flow communication with said internalpassage; said spool including a resilient sealing means secured theretofor movement therewith, from a position between said first and secondflow means, past said first flow means to a position between said firstflow means and said lateral passage; said lateral passage including athird means for conducting a flow of fluid through said valve body andbeing in flow communication with said passage.
 5. The spool valve ofclaim 4 in which said second fluid flow means comprises a second passageextending laterally of and into said internal passage and said firstfluid flow means comprises a plurality of adjacent passages extendinglaterally of and into said internal passage whose combinedcross-sectional area is equal to or greater than the cross-sectionalarea of said second lateral passage.
 6. A spool valve comprising a spoolmounted in a valve body for controlling fluid flow therethrough inresponse to axial spool movements; an internal passage within said valvebody, and said spool disposed in said passage; means for securing atleast two fluid lines to said valve body, between which flow is to becontrolled; said fluid line-connecting means comprising one lateralpassage connecting one such line to said internal passage and at leasttwo lateral passages connecting the other such line to said internalpassage, the combined cross-sectional area of said two passages beingapproximately equal to or greater than the cross-sectional area of saidone passage; a resilient sealing member being secured to said spool in aposition for movement with said spool from a position between said onelateral passage and said two lateral passages past said two lateralpassages, whereby all of said lateral passages communicate through saidinternal spool passage.